Genetic counseling: Arthrogryposis
Arthrogryposis Contracting *Acknowledge prior phone contact *What questions or concerns would you like to address today? *Overview of agenda for the session Intake and Family History *Pregnancy and medical history **Maternal fever or viruses during pregnancy? **Oligohydramnios or unusually shaped uterus? (Crumply ears, thin or hyperextensible skin?) **Was the baby active throughout the pregnancy? **Any problems with hands, wrists, elbows, shoulders, knees, jaw, or back? **Any muscle weakness or hypotonia? **Has she had any muscle biopsies or other blood tests to rule out possible disorders? *Family history **Anyone else with club foot, joint dislocations, scoliosis? **Individuals who are short in stature? **Anyone with any muscular dystrophy, muscle disease, muscle weakness? **Anyone with cleft lip and/or palate, hearing loss, mental retardation? Etiology *Condition describing the presence of multiple joint contractures at birth **Joint contractures are limitations in the range of motion of joints **May affect few or all joints to varying degrees ***Includes hands, wrists, elbows, shoulders, hips, feet, and knees ***Severe cases may include the jaw and back *Can be caused by anything that prevents normal joint movement before birth **When joint is not moved, extra connective tissue may grow around it and fix it in position **Tendons connecting to joint not stretched to normal length, making joint movement difficult *Four possible reasons for limitation of joint movement prenatally **Muscles do not develop properly (atrophy) ***Muscle diseases, including congenital muscular dystrophies ***Maternal fever during pregnancy ***Viruses that damage cells transmitting nerve impulses to muscle **There is not sufficient room in the uterus for normal movement ***Oligohydramnios ***Abnormally shaped uterus that causes crowding **Central nervous system or spinal cord malformations **Tendons, bones, joints, or joint linings don't develop properly *May be environmental or genetic depending on cause of contractures **Genetic cause identified in about 30% of cases **Incidence is about 1 in 3000 live births Causes of Arthrogryposis *Diagnosis usually made by ruling out other causes or syndromes *Cartilaginous abnormalities **Beal Syndrome ***Linked to fibrillin locus on chromosome 5q23-31 ***Autosomal dominant ***Crumpled ears, long slim limbs and fingers, frontal bossing, short neck **Antley-Bixer Syndrome ***No confirmatory testing ***Probably autosomal recessive ***Crouzon syndrome-like appearance and midface hypoplasia **Distal Arthrogryposis Syndrome ***Autosomal dominant with variable expression ***Facial features usually normal ***Arthrogryposis of hands and lesser extent feet *Physical constraint to movement **Oligohydramnios Sequence ***Diagnosis made by clinical findings ***Arthrogryposis usually involves knees and feet ***Wrinkled skin, squashed nose, low-set ears, short neck ***Often secondary to bilateral renal agenesis **Escobar Syndrome ***Autosomal recessive condition ***Thick skin folds keep joints in fixed position ***Restrict joint motility in neck, axilla, antecubital, popliteal, and digital areas *Neurological Abnormalities **Trisomy 18 and Trisomy 13 ***Cause distal arthrogryposis ***Causes severe mental retardation and facial dysmorphism **Smith-Lemli-Opitz ***Autosomal recessive condition ***Due to defect in cholesterol biosynthesis leading to severe MR and early death ***Microcephaly, cryptorchidism, hypospadias, and arthrogryposis of hands **Zellweger Syndrome ***Caused by genetic mutations at 7q11.23 and 1p22-21 ***Autosomal recessive inheritance ***Severe hypotonia, brachycephaly, open fontanels, cryptorchidism, hypospadias, and distal arthrogryposis **Infantile Spinal Muscular Atrophy ***Autosomal recessive and X-linked inheritance ***Arthrogryposis occurs in 10-20% of neonates with SMA **Moebius Syndrome ***Sporadic or autosomal dominant in some cases ***Causes bilateral facial weakness and arthrogryposis in about 30% patients **Congenital Myotonic Dystrophy ***Due to trinucleotide repeat expansion at 19q13 ***Autosomal dominant disorder ***Marked body and facial hypotonia with arthrogryposis in lower extremities **Congenital Muscular Dystrophy ***Inheritance pattern varies depending on type of muscular dystrophy ***Hypotonia, muscle weakness, and distal arthrogryposis ***Serum creatine kinase may be normal or elevated Clinical Manifestations and Natural History *Wide variation in degree to which muscles and joints are affected **May be accompanied by other conditions tat complicate the picture **Outlook is generally very positive *Not a progressive condition **Substantial improvements seen with treatment **Most individuals are of normal intelligence and lead independent lives as adults *Possible features **Head and neck ***Facial asymmetry ***Micrognathia, notched chin, or malar hypoplasia ***Immobile facies ***Low-set posteriorly located ears or overfolded helices ***High nasal bridge ***Highly arched palate, cleft lip, or cleft palate ***Eyes ****Keratoconus ****Downslanting palpebral fissures ****Blepharoptosis, hypertelorism, or ophthalmoplegia ****Retinopathy ***Short neck, fused cervical vertebrae, and pterygia **Chest deformities **Inguinal hernia **Hand and foot ****Overlapping fingers, tapered fingers, camptodactyly, or syndactyly ***Clenched fists ***Positional foot deformities or clubfoot ***Single or bridged palmar creases ***Absent or hypoplastic distal flexion creases **Extremities ***Radial head dislocation, contractures, and limitation of motion ***Affects shoulder, elbow, wrist, knee, ankle, and hip joints **Scoliosis and kyphosis **Microphallus and cryptorchidism **Elevated serum creatine phosphokinase *Occasional growth and mental retardation Treatment/Management *First important to determine the cause **Influences prognosis, recurrence risk, and treatment ***Definite diagnosis may not be possible in neonatal period ***Important to separate neurological from non-neurological causes **MRI study for infants with neurological findings suggesting brain or spinal cord involvement **Chromosome analysis or genetic testing for those who appear to have genetic syndrome *Physical therapy **Helps improve muscle strength and range of motion **Includes stretching, strengthening, mobility training, and training in ADL skills *Casting or splinting **Splints can augment stretching to increase range of motion **Casting can improve foot position **Removable splint such as bi-valve cast or wearing splint at night often still allows motion and stretching *Surgeries **Usually considered supportive measure to other forms of treatment **Performed on ankles to put feet in weight-bearing position **Tendon transfers can sometimes improve muscle function Psychosocial Issues *Parental concern over underlying cause of condition *Reaction to infant requiring braces, casts, or surgeries *Difficulty bonding with a child who looks different or requires special care *Guilt, depression, anger over new diagnosis *Concern for child's future Support Resources *National Support Group for Arthrogryposis :AVENUES :Phone: 209-928-3688 :Web: http://www.sonnet.com/avenues :Email: avenues@sonnet.com *NORD (National Organization of Rare Disorders) :Web: http://www.raredisease.org References *Alfonson I, et al. "Arthrogryposis Multiplex Congenita." International Pediatrics (2000) 15:4;197-204. *"Arthrogryposis Multiplex Congenita." Multiple Congenital Anomaly/Mental Retardation Syndromes: US National Library of Medicine. http://www.nlm.nih.gov *"What is Arthrogryposis?" Published by AVENUES. http://www.sonnet.com/avenues Notes The information in this outline was last updated in 2002. Material obtained under GFDL Licence from http://en.wikibooks.org/wiki/Handbook_of_Genetic_Counseling